Operator control system for self-propelled vehicles

ABSTRACT

An operator control system for a self-propelled vehicle such as a lawn mower is provided wherein the control system includes two opposing and preferably upwardly extending and converging hand grips each having a corresponding drive control lever associated therewith. Each drive control lever may have at least a portion that is parallel to a grip axis of its respective hand grip. Further, each drive control lever may have a pivot axis that is substantially parallel to the corresponding grip axis such that the drive control lever remains substantially parallel to its respective hand grip throughout its travel. A latching device may be provided to permit latching of each drive control lever in two or more positions, e.g., a neutral position and a park position. Secondary levers such as operator presence control (OPC) levers may also be included.

[0001] This is a continuation-in-part of U.S. patent application Ser.No. 09/893,193, filed Jun. 27, 2001 (pending), which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates generally to self-propelled,ground-working vehicles such as lawn mowers and, more particularly, tooperator control systems for use with the same.

BACKGROUND OF THE INVENTION

[0003] Various types of lawn mowers are known. For example, small,walk-behind mowers are in general use by both homeowners andprofessionals alike. At the other end of the spectrum are large, ridingmowers adept at mowing correspondingly large and typically unobstructedareas. Between these two categories lies what is commonly referred to as“mid-size” mowers.

[0004] Generally speaking, mid-size mowers are self-propelled unitshaving a cutting width of approximately 32-60 inches. While they may beconfigured as either riding (including ride-on and ride-behind) orwalk-behind units, walk-behind mowers potentially offer greatermaneuverability. For example, walk-behind mowers are particularlyefficient when mowing large lawns having numerous obstacles (e.g.,trees, shrubs, flowerbeds, and the like) which necessitate intricatetrimming, or when mowing lawns which may otherwise be ill-suited tohigh-speed riding mowers. Moreover, walk-behind mowers are often used inareas with steep slopes which may pose traction or tipping problems forriding mowers. Furthermore, mid-size, walk-behind mowers are also, ingeneral, less expensive than riding mowers. While the present inventionis directed to control systems for use with either riding or walk-behindvehicles, it will, for the sake of brevity, be described with respect tomid-size, walk-behind mowers.

[0005] One type of control system known for use with mid-size mowersuses two rearwardly extending handles each equipped with a scissors-typelever. Each lever operatively controls one of two drive wheels typicallylocated at or near the rear corners of the cutting unit. Where thelevers are configured as “normally engaged,” actuating (e.g., squeezing)one of the drive levers causes disengagement and/or braking of thecorresponding drive wheel, permitting the mower to turn about thatwheel. Alternatively, the levers may be “normally disengaged” such thatactuating (e.g., squeezing) one of the drive levers causes engagement ofthe corresponding drive wheel.

[0006] While scissors-type lever control systems are more than adequatefor their intended purpose, drawbacks remain. For instance,scissors-type levers, in general, may provide limited mechanicaladvantage in overcoming lever tension. Accordingly, when cutting a lawnwith many trees, shrubs, or other obstacles that necessitate numerousturns, discomfort in the hands, wrists, and arms may occur.Scissors-type lever control systems may also be susceptible to variationin lever tension over the lever travel. Furthermore, depending on theposition of each lever within its throw, the operator may not be able tograsp the respective lever with all fingers.

[0007] Other systems are also known. For example, U.S. Pat. Nos.5,511,367 to Powers et al. and 5,809,755 to Velke et al. disclosecontrol systems having a generally horizontal, transverse hand position.While addressing some of the above-identified problems, other issueswith hand position and/or control actuation potentially remain.

SUMMARY OF THE INVENTION

[0008] Control systems of the present invention seek to overcome theabove-identified drawbacks by providing natural hand positioning withconveniently located drive control levers. Control systems in accordancewith the present invention further provide a hand position interior tothe control system to reduce potential contact between the operator'shands and external objects during operation. The drive control levers ofthe present invention may additionally provide substantially constanttension throughout their range of motion, resulting in drive controllever forces which are more evenly distributed throughout the operator'shands.

[0009] In one embodiment, an operator control system for aself-propelled vehicle is provided. The operator control system includesa handle assembly including a first hand grip having a first grip axisand a second hand grip having a second grip axis. The first grip axisand the second grip axis extend upwardly and toward one another when thevehicle is in an operating configuration. A first control leverassociated with the first hand grip is also included. The first controllever is pivotable about a first pivot axis, wherein the first pivotaxis is substantially parallel to the first grip axis of the first handgrip. A latching device associated with the first control lever is alsoincluded and is adapted to latch the first control lever in two or morepositions.

[0010] In another embodiment, an operator control system for aself-propelled vehicle is provided and includes a handle assemblyincluding a first hand grip having a first grip axis and a second handgrip having a second grip axis. The first grip axis and the second gripaxis extend upwardly, forwardly, and toward one another when the vehicleis in an operating configuration. Also provided is a first control leverassociated with the first hand grip. The first control lever ispivotable about a first pivot axis, wherein the first pivot axis issubstantially parallel to the first grip axis of the first hand grip. Alatching device associated with the first control lever is alsoincluded. The latching device is operable to latch the first controllever in two or more positions.

[0011] In yet another embodiment, a method for controlling aself-propelled vehicle is provided. The method includes providing anoperator control system including a handle assembly having a first handgrip with a first grip axis and a second hand grip with a second gripaxis. The first grip axis and the second grip axis extend upwardly andtoward one another when the vehicle is in an operating configuration. Afirst control lever associated with the first hand grip is alsoincluded. The first control lever is pivotable about a first pivot axis,wherein the first pivot axis is substantially parallel to the first gripaxis of the first hand grip. The handle assembly also includes a firstlatching device associated with the first control lever, where the firstlatching device is operable to latch the first control lever in at leasta first position and a second position. The method also includes:grasping the first control lever with an operator's first hand;manipulating the first control lever to the first position with theoperator's first hand; and manipulating the first latching device tolatch the first control lever in the first position.

[0012] In still yet another embodiment, an operator control system for aself-propelled power mower is provided. In this embodiment, the controlsystem may include a handle assembly including a first hand grip havinga first grip axis and a second hand grip having a second grip axis. Thefirst grip axis and the second grip axis are substantially coplanar andextend upwardly, forwardly, and toward one another when the mower is inan operating configuration. The control system may also include a firstcontrol lever associated with the first hand grip, where the firstcontrol lever is pivotable about a first pivot axis, the first pivotaxis being substantially parallel to the first grip axis of the firsthand grip. A first latching device including a generally hook-shapedmember pivotally coupled to the first hand grip is also included. Thefirst latching device is operable to pivot about an axis generallycoaxial with the first grip axis. The first latching device is adaptedto latch the first control lever in at least a first position and asecond position.

[0013] The above summary of the invention is not intended to describeeach embodiment or every implementation of the present invention.Rather, a more complete understanding of the invention will becomeapparent and appreciated by reference to the following detaileddescription and claims in view of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described with reference tothe drawings, wherein:

[0015]FIG. 1 is a left front perspective view of a self-propelledvehicle, e.g., a mid-size, walk-behind mower, incorporating an operatorcontrol system in accordance with one embodiment of the presentinvention;

[0016]FIG. 2 is an enlarged, partial perspective view of the operatorcontrol system of FIG. 1;

[0017]FIG. 3 is a left rear perspective view of the operator controlsystem of FIG. 1;

[0018]FIG. 4 is a top plan view of the operator control system of FIG.1;

[0019]FIG. 5 is a partial perspective view of a right side portion ofthe control system of FIG. 1 with a left side portion removed forclarity;

[0020] FIGS. 6-10 are enlarged views of a neutral position latchingdevice shown in various positions, (FIG. 6 illustrates a drive controllever secured in a first or neutral position by the latching device;FIG. 7 illustrates the latching device pivoted for release of the drivecontrol lever; FIG. 8 illustrates the drive control lever in a second orforward position relative to the latching device; FIG. 9 illustrates thelatching device relative to the drive control lever while the latter isin the second position; and FIG. 10 illustrates the latching devicerelative to the drive control lever while the latter is in a third orreverse position);

[0021]FIG. 11 is an enlarged section view taken along line 11-11 of FIG.4 illustrating the cross-sectional shape of an operator presence controllever;

[0022]FIG. 12 is an enlarged end view of a portion of the operatorpresence control lever of FIG. 11;

[0023]FIG. 13 is a side elevation view of an operator control system inaccordance with another embodiment of the invention;

[0024]FIG. 14 is a partial side elevation view of a mid-size,walk-behind power mower in accordance with another embodiment of theinvention; and

[0025] FIGS. 15-19 are enlarged views of a latching device in accordancewith another embodiment of the invention (FIG. 15 illustrates a drivecontrol lever latched in a neutral position by the latching device; FIG.16 illustrates the latching device pivoted for release of the drivecontrol lever; FIG. 17 illustrates the drive control lever latched in apark position by the latching device; FIG. 18 illustrates the drivecontrol lever in a forward position relative to the latching device; andFIG. 19 illustrates the latching device relative to the drive controllever while the latter is in the park position).

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0026] In the following detailed description of the embodiments,reference is made to the accompanying drawings which form a part hereof,and in which are shown by way of illustration specific embodiments inwhich the invention may be practiced. It is to be understood that otherembodiments may be utilized and structural changes may be made withoutdeparting from the scope of the present invention.

[0027]FIG. 1 shows an operator control system 200 in accordance with oneembodiment of the present invention as the latter may be incorporated ona self-propelled vehicle, e.g., a mid-size, walk-behind lawn mower 100.While, for the sake of brevity, the invention is herein described withrespect to a particular mid-size, walk-behind lawn mower (hereinaftergenerically referred to merely as “walk-behind mower,” or, moregenerally, as “mower”), those of skill in the art will realize that theinvention is equally applicable to other walk-behind mowers, ride-behindmowers (e.g., such as those utilizing sulkies), and conventional ride-onmowers as well as to most any other walk-behind, ride-behind, or ride-onself-propelled, ground working vehicle, e.g., skid-steer loader,aerator, snow thrower, tiller, etc.

[0028] While the general construction of the mower 100 is not consideredcentral to the invention, it will now be briefly described. FIG. 1illustrates an exemplary mower 100 (shown primarily in broken lines)having a frame 102 supporting a prime mover, e.g., internal combustionengine 104. A pair of transversely opposing, ground engaging drivewheels 106 (only left wheel visible) may support the rear of the mower100 in rolling engagement with the ground. Each drive wheel 106 may bepowered by a hydraulic motor (not shown) which receives hydraulic powerfrom a hydraulic pump 107 (best shown in FIG. 3) under the control ofvarious operator-controlled valves. The hydraulic pumps 107, in turn,may be separately powered by the engine 104. Other drive systems, e.g.,gear or pulley driven systems (examples of which are described below),are also within the scope of the invention.

[0029] Operator controls, as further described below, permit independentcontrol of the speed and direction of each drive wheel 106, allowingcontrol of mower speed and direction from a walking or riding positiongenerally aft, e.g., behind, the mower 100. A pair of front swivelingcaster wheels 108, which are preferably connected to forwardly extendingframe rails 102 a and 102 b, may support the front of the mower 100 inrolling engagement with the ground.

[0030] As used herein, relative terms such as “left,” “right,” “fore,”“forward,” “aft,” “rearward,” “top,” “bottom,” “upper,” “lower,”“horizontal,” “vertical,” and the like are from the perspective of oneoperating the mower 100 while the mower is in an operatingconfiguration, e.g., while the mower 100 is positioned such that thewheels 106 and 108 rest upon a generally horizontal ground surface asshown in FIG. 1. These terms are used herein to simplify thedescription, however, and not to limit the scope of the invention in anyway.

[0031] Although the illustrated mower 100 has the drive wheels 106 inthe rear and the caster wheels 108 in front, this configuration is notlimiting. For example, other embodiments may reverse the location of thewheels, e.g., drive wheels in front and caster wheels in back. Moreover,other configurations may use different wheel configurations altogether,e.g., a tri-wheel configuration. These and other embodiments arepossible without departing from the scope of the invention.

[0032] A cutting deck 114 may be mounted to a lower side of the frame102 generally between the drive wheels 106 and the caster wheels 108.The cutting deck 114 includes one or more cutting blades (not shown) asknown in the art which are operatively powered by the engine 104. Duringoperation, power is selectively delivered to the cutting deck 114,whereby the blades rotate at a speed sufficient to sever grass and othervegetation passing underneath the cutting deck. The cutting deck 114 mayoptionally include deck rollers 115 to further support the cutting deckrelative to the ground during operation.

[0033] As illustrated in FIGS. 2-3, the operator control system 200 mayinclude a first hand grip 202 a and a second hand grip 202 b. To supportthe operator control system 200, one or more structural members such asarms 116 may extend between the frame 102 and the control system 200,e.g., the arms 116 may extend upwardly and rearwardly from the frame 102(best shown in FIG. 1). While shown and described as arms 116, most anycomparable structure is possible without departing from the scope of theinvention. For example, plate and/or sheet metal structures may be usedin place of, or in addition to, the arms 116.

[0034] The suffixes “a” and “b” are used throughout this description todenote various left and right side parts/features, respectively.However, in most pertinent respects, the parts/features denoted with “a”and “b” suffixes are either substantially identical to, or mirror imagesof, one another. Therefore, such items may, where appropriate, bereferred to generically or collectively without the suffix, e.g., “handgrip 202” may refer to either or both hand grip 202 a and hand grip 202b. It is understood that, unless otherwise noted, the description of anindividual part/feature, e.g., the description of a part/featureidentified with an “a” suffix, also applies to the opposingpart/feature, e.g., the part/feature identified with a “b” suffix.Similarly, the description of a part/feature identified with no suffixapplies to both the corresponding left and right part/feature, e.g., toboth the part/feature identified with the “a” suffix and the “b” suffix.

[0035] In some embodiments, the hand grips 202 form ends of a continuoushandle assembly 203 which may also include a substantially transversetube member or portion 204 and curved portions 206 as shown in FIG. 3.As the figures illustrate, the curved portions 206 and hand grips 202may result in a generally bull-horn shaped handle assembly 203.

[0036] The bull-horn shape of the handle assembly 203 yields hand grips202 that are preferably generally inclined upwardly and toward oneanother. In other words, a first grip axis 201 a of the first grip 202 amay approach a second grip axis 201 b of the second grip 202 b at apoint above the handle assembly 203 as shown in FIG. 2. Preferably,although not necessarily, the hand grips 202 are generally straight andlie within a common plane (e.g., the grip axis 201 a of the hand grip202 a may be coplanar with the grip axis 201 b of the hand grip 202 b).In embodiments where the hand grips 202 do lie within the same plane,the grip axis 201 a may intersect the grip axis 201 b at a point abovethe handle assembly 203. While not limited thereto, the grip axis 201 ofeach hand grip 202 may be inclined at an angle 210 (see FIG. 3) of 30degrees to 60 degrees and, more preferably, at an angle 210 of 30 to 40degrees, measured from a respective line 205 formed by the intersectionof the plane of the hand grips 202 and a vertical plane.

[0037] The hand grips 202 may also be inclined forwardly relative to avertical plane passing through a lowermost portion of the handleassembly 203, e.g., passing through a lowermost portion of the firsthand grip 202 a, as generally indicated in the figures (see e.g., FIG.13). While not limited thereto, some embodiments may be configured withthe hand grips 202 inclined forwardly from the vertical plane at anangle 208 (see FIG. 13) of between 30 degrees and 60 degrees and, morepreferably, at an angle 208 between 30 degrees and 40 degrees.

[0038] As those of skill in the art will realize, the shape andorientation of the handle assembly 203, e.g., the hand grips 202,provide the operator with comfortable hand positioning during operation(see FIG. 2). Further, by positioning the operator's hands interior tothe periphery of the handle assembly 203, e.g., inboard or interior tothe curved portions 206, the chance of inadvertent contact between thehands and obstacles during operation may be reduced.

[0039] The handle assembly 203 may attach to the arms 116 in any numberof ways. For example, the handle assembly 203 may be welded to the arms116 as shown in FIG. 4. Alternatively, the handle assembly 203 may befastened to the arms 116 using, for example, mechanical fasteners,adhesives, or the like. In still other embodiments, the hand grips 202may be integrally formed with the arms 116, e.g., the ends of arms 116may form the hand grips 202. In the case of the latter, the transversetube portion 204, the curved portions 206, or both, may be optional.

[0040] Various control devices are mounted on or in close proximity tothe handle assembly 203 as illustrated in FIG. 3. For example, atransmission lever 212 may be provided to allow drive parameterselection, e.g., forward speed, while a throttle 214 may be provided tocontrol engine speed. Other controls not central to the invention, e.g.,starter, choke, etc., although not illustrated, may also be provided. Acover 216 may be further included to offer a more aesthetically pleasingappearance as well as to shield various moving parts.

[0041] To control power delivery to the drive wheels 106, the operatorcontrol system 200 preferably includes a first control lever, e.g., afirst drive control lever 220 a, and a second control lever, e.g., asecond drive control lever 220 b, as clearly illustrated in FIGS. 3 and4. The drive control levers 220 are coupled to respective hydraulicpumps 107 via tie rods 222. When a drive control lever 220 ismanipulated as described below, the corresponding tie rod 222 pivots alever arm 224 on the pump 107, manipulating a hydraulic valve (notshown) which controls hydraulic flow to the respective drive wheel motor(also not shown).

[0042] Each drive control lever 220 preferably has a shape similar tothe corresponding hand grip 202 as shown in FIG. 4, e.g., the drivecontrol lever 220 a, similar to the drive control lever 220 b, may havea grip portion 226 a defining a lever axis 227 a substantially parallelto the grip axis 201 a of the respective hand grip 202 a. Optionally,each drive control lever 220 may include a curved portion 228 having ashape that generally corresponds to the shape of the respective curvedportion 206, e.g., curved portion 228 a may have generally the sameradius of curvature as the respective curved portion 206. While the gripportion 226 is described and illustrated as straight, other shapes arealso possible without departing from the scope of the invention.

[0043] Each drive control lever 220 may pivotally couple to the mower100 (e.g., to the handle assembly 203 or, as shown in FIG. 4, to thearms 116) via a pivot assembly 232. Preferably, the pivot assembly 232permits pivoting of the drive control lever 220 about an axissubstantially parallel to the respective hand grip 202, e.g., the drivecontrol lever 220 a pivots about a pivot axis 230 a that issubstantially parallel to the grip axis 201 a of the hand grip 202 a.The tie rod 222 is coupled to the drive control lever 220 at a tie rodpivot 234 (see FIGS. 3 and 5) located a predetermined distance from thepivot axis 230 to provide the desired tie rod movement for a given drivecontrol lever 220 movement.

[0044] Because of the substantially parallel orientation of the pivotaxis 230 to the axes 201 and 227, the lever axis 227 of the drivecontrol lever 220 remains generally parallel to the grip axis 201 of therespective hand grip 202 throughout the range of motion of the drivecontrol lever 220, e.g., the grip portion 226 a of the drive controllever 220 a remains parallel to its respective hand grip 202 a. As aresult, the force required to manipulate each drive control lever 220 issubstantially uniform throughout the travel of the drive control lever220. Moreover, because the lever axis 227 of the drive control lever 220is parallel to the grip axis 201 of the hand grip 202, the operator isable to grasp the drive control lever 220 with most, if not all, fingers(see FIG. 2) regardless of the particular position of the drive controllever within its travel.

[0045] To further improve operator comfort during mower 100 use, eachdrive control lever 220 may have a cross section defined by one or morecurved surfaces. For example, FIG. 5 illustrates an exemplary gripportion 226 b with a curved, e.g., convex or semi-cylindrical, surface236 and a generally planar surface 238. Other embodiments may include aconcave surface in place of the planar surface 238 such that the drivecontrol lever 220 corresponds to the shape of the hand grip 202 when thedrive control lever 220 is proximate thereto. Other embodiments may varythe shape or the radius of curvature of the curved surface 236.Preferably, the curved surface 236 permits grasping by the operatorwithout resulting in excessive pressure at any point along theoperator's fingers.

[0046]FIG. 5 also illustrates the range of motion of the drive controllever 220. In this figure, the drive control lever 220 b is illustratedin solid lines in a forward position identified as “F.” Preferably, thedrive control levers 220 are biased toward the forward position F. Theforward position F corresponds to the respective hydraulic pump 107 (seeFIG. 3) providing maximum hydraulic flow for forward motion of the mower100. Each drive control lever 220 may also be movable to a reverseposition “R” by squeezing the drive control lever 220, e.g., drivecontrol lever 220 b, toward the hand grip 202, e.g., hand grip 202 b.The reverse position R corresponds to the respective hydraulic pump 107(see FIG. 3) providing maximum hydraulic flow for reverse motion of themower 100.

[0047] Each drive control lever 220 may also be movable to any positionbetween the forward position F and the reverse position R. In someembodiments, the drive control lever 220, when in an intermediate orneutral position, e.g., a position identified as N in broken lines inFIG. 5, may place the respective hydraulic pump 107 (see FIG. 3) in astatic configuration. That is, when the drive control lever 220 is inthe neutral position N, differential flow output from the pump 107 maybe effectively terminated such that no driving power is delivered to therespective drive wheel 106. In some embodiments, the neutral position Ncould configure internal valving of the respective hydraulic pump 107into a cross-ported configuration such that the respective drive wheel106 could freewheel without substantial hydraulic resistance. As aresult, the mower 100 could, when both drive control levers 220 are inthe neutral position N, be moved without starting the engine.

[0048] Accordingly, drive control systems in accordance with the presentinvention provide intuitive control of the mower 100. For instance,incremental forward movement of both drive control levers 220 from theneutral position N to the forward position F results in forwardpropulsion of the mower 100 at incrementally increasing speed.Similarly, incremental rearward motion of both drive control levers 220from the neutral position N to the reverse position R results inincrementally increasing reverse speed. By manipulating the drivecontrol lever 220 a and drive control lever 220 b independently betweenthe forward position F and the reverse position R, the operator cancontrol both speed and direction of the mower 100. For example, whileone drive control lever, e.g., 220 a, may be commanded for mowermovement in a first direction at a first speed, the opposite drivecontrol lever, e.g., 220 b, may be commanded for mower movement in thesame or opposite direction at the same or different speed.

[0049] Some embodiments of the present invention may optionally includea latching device, e.g., a neutral lock 270, of which one configurationis shown in FIG. 5. The neutral lock 270 permits the operator totemporarily lock the drive control lever 220 in at least onepredetermined position, e.g., in the neutral position N. By permittinglocking of each drive control lever 220 in the neutral position N, theoperator may suspend operation and release one or more secondary levers,e.g., an operator presence control (hereinafter “OPC”) lever 240 furtherdescribed below, without inadvertently stopping the engine 104.

[0050] FIGS. 6-10 illustrate end views of the hand grip 202 b showingthe neutral lock 270 in various positions relative to the drive controllever 220 b. The hand grip 202 a also preferably includes a neutral lock270 (see e.g., FIG. 3) which operates in a manner generally identical tothat described below.

[0051] In the embodiments illustrated herein, the neutral lock 270 ispivotable about an end of the hand grip 202 b, e.g., about a latch pivotaxis 272 which may be generally parallel and preferably coaxial to thegrip axis 201 b of the hand grip 202 b (see FIG. 4), between a lockedposition (see FIG. 6) and an unlocked position (see FIG. 7).

[0052] The neutral lock 270 may include a hook portion 274 for capturingthe drive control lever 220 b when the latter is in the first or neutralposition N as generally shown in FIG. 6. To disengage the neutral lock270 from the locked position of FIG. 6, it may be manually pivoted aboutthe latch pivot axis 272 in a direction 275 to the unlocked positionillustrated in FIG. 7. While the neutral lock 270, as illustrated inFIGS. 5 and 6-10, may be configured with an outwardly opening mouth,other embodiments may utilize a neutral lock 270 having an inwardlyopening mouth as generally shown in FIGS. 1 and 2. To assist theoperator with pivoting the neutral lock 270, thumb tabs 276 and 278 maybe included. Optionally, a friction-reducing member/device, e.g., aroller 280, may be provided to assist with moving the neutral lock 270relative to the drive control lever 220 b.

[0053] To provide rotational resistance to the neutral lock 270, afriction device (not shown) may be incorporated. For example, theneutral lock 270 may be fastened to the hand grip 202 b with a fastenerand one or more spring disc washers as known in the art. By controllingthe installation torque of the fastener, the axial clamping forceapplied to the neutral lock 270 by the spring washers may be varied,thus altering the resistance of the neutral lock 270 to rotationalmovement. Other friction devices may also be used without departing fromthe scope of the invention.

[0054] Once the neutral lock 270 is moved to the unlocked positionillustrated in FIG. 7, the drive control lever 220 b is free to move tothe forward position F as shown in FIG. 8. A pivot limiting device,e.g., ear 282 as shown in FIG. 9, may be included with the neutral lock270 to prevent engagement of the neutral lock 270, e.g., rotation of theneutral lock 270 in the direction 284, when the drive control lever 220b is in the forward position F. FIG. 10 illustrates the relativelocations of the drive control lever 220 b and the neutral lock 270 whenthe drive control lever 220 b is in the reverse position R.

[0055] Various embodiments of operator control systems in accordancewith the present invention may further include one or more operatorpresence control (OPC) devices as shown in FIGS. 4 and 5. OPC devicesare typically configured to terminate mower operation, e.g., stop theengine 104, in some circumstances unless operator presence is detected.In the instant invention, the OPC device may be configured as one ormore secondary or OPC levers 240 positioned proximate the respectivehand grips 202 opposite the drive control lever 220, e.g., aft of thehand grip. Like the drive control lever 220, each OPC lever 240 mayinclude a generally straight gripping portion 242 and a curved portion244. The gripping portion 242 and the curved portion 244 have shapesthat may generally correspond to that of the hand grip 202 and thecurved portion 206, respectively.

[0056] OPC levers 240 in accordance with the present invention mayoperatively couple to an interlock switch 249 (as known in the art anddiagrammatically represented in FIG. 4) and manipulate the same betweenan open configuration and a closed configuration. Generally speaking,mower, e.g., engine 104, operation is disabled when the interlock switch249 is in its open configuration and enabled when the interlock switch249 is in its closed configuration.

[0057] The OPC levers 240 are preferably biased toward a disengaged,normally open position identified as “O” in broken lines in FIG. 5. Theopen position O preferably corresponds to the interlock switch 249 beingin its open configuration (mower disabled). To operate the mower 100, atleast one of the OPC levers 240 may be squeezed toward the respectivehand grip 202 to a closed, e.g., engaged, position identified as “C” insolid lines in FIG. 5. The closed position C preferably corresponds tothe interlock switch 249 being in its closed configuration (mowerenabled).

[0058] In some embodiments, the OPC lever 240 may be movable between theopen position O and the closed position C by pivoting about an OPC pivot246 having a pivot axis 248 that is generally transverse to alongitudinal axis 150 of the mower 100 as shown in FIG. 4. The grippingportions 242 may each, in some embodiments, define a secondary leveraxis 243 (see e.g., axis 243 b in FIG. 5) which is substantiallyparallel to the grip axis 201 of the respective hand grip 202 when theOPC lever 240 is in the closed position C.

[0059] Preferably, one OPC lever 240 is associated with each hand grip202, e.g., OPC levers 240 a and 240 b may be provided as shown in FIG.4. The OPC levers 240 may further be configured such that they form asingle lever. As a result, the operator may engage the interlock switch249 with one OPC lever 240, e.g., the interlock switch may be engaged byholding either one or both OPC levers 240 a and 240 b in the closedposition C (see FIG. 5). However, should the operator release bothlevers 240 a and 240 b, they will return to their open position O,opening the interlock switch 249 and thus disabling the mower 100, e.g.,engine 104, from further operation.

[0060] Like the drive control levers 220, the OPC levers 240 may beconfigured to assist in reducing operator fatigue. For example, thecross-sectional shape of at least the gripping portion 242 (see e.g.,242 b in FIG. 5) may be configured to generally correspond to theexterior profile of the hand grip 202 as shown in FIG. 11.

[0061] As illustrated in FIG. 1, each hand grip 202 may include a rigidor semi-rigid core portion 286 which, in one embodiment, is made fromsteel or aluminum. To provide more comfortable gripping, the coreportion 286 of the hand grip 202 may optionally be surrounded, at leastin part, by a gripping layer 288. While not limited thereto, thegripping layer 288 may preferably be made from a compressible materialsuch as foam rubber. As FIG. 11 illustrates, the gripping layer 288defines an outer radius 290 of the hand grip 202.

[0062] The OPC lever 240 may define a cross-sectional shape having asurface 292 which preferably conforms to a cross-sectional shape of thehand grip 202 when the OPC lever 240 is in the closed position C (asshown in FIG. 11). In the illustrated embodiment of FIGS. 11 and 12, thesurface 292 is concave having an inner radius 291 generally equal insize to the outer radius 290. As a result, the OPC lever 240 contactsthe hand grip 202 along most, if not all, of the surface 292.

[0063] The OPC lever 240 may be further defined by a convex surface 294having a radius 296. Preferably, the radius 296 of the convex surface294 is less than the radius of the concave surface 292, e.g., the radii291 and 296 have different centers. This geometry yields acrescent-shaped cross-section as shown in FIG. 12. To avoid sharp edgesand to provide a smooth transition to the gripping layer 288, the twosurfaces 292 and 294 may blend together at a radius 298.

[0064] Providing an OPC cross-sectional shape as described above andshown in FIGS. 11 and 12 results in generally smooth transition zonesfrom the edges of the gripping portion 242 of the OPC lever 240 to thehand grips 202. Also, the eccentric surfaces 292 and 294 result in theOPC lever gripping portion 242 having a non-uniform thickness, e.g.,being somewhat thicker near its middle than near its edges (see FIG.12). The thicker middle portion provides the operator with a protrusionto grip during operation while the thinner edges provide a gradualtransition from the gripping portion 242 to the hand grip 202. As aresult, the transition from the OPC lever 240 to the hand grip 202produces relatively few pressure points.

[0065] As noted above, the embodiments described and illustrated hereinare exemplary only. Other configurations are certainly possible withoutdeparting from the scope of the invention. For example, the hand grips202 may have different cross-sectional shapes, e.g., an oval. When soconfigured, various corresponding surfaces, e.g., the surface 292 of theOPC lever 240 (see FIG. 12) and/or the surface 238 of the drive controllever 220 (See FIG. 5) may be reconfigured to correspond to the newcross-sectional shape of the hand grip 202.

[0066] The OPC lever 240 may also be configured to pivot about an axisgenerally parallel to the grip axis 201 of the hand grip 202 (see FIG.4) rather than about the transverse axis 248 (see also FIG. 4) describedherein.

[0067] In still other embodiments, an operator control system 300 may beconfigured such that a drive control lever 320 is located aft of, i.e.,behind, the hand grip 202 as shown in FIG. 13. The drive control lever320 may still pivot about a pivot assembly 322 having a pivot axissubstantially parallel to an axis of the hand grip 202. Movement of thedrive control lever 320 may reposition the tie rod 222 as describedabove. While not shown, neutral locks and OPC levers may be reconfiguredto accommodate this revised drive control lever structure.

[0068] While described above specifically with application tohydraulically-powered mowers, the present invention is equallyapplicable to vehicles utilizing other drive systems. For example, awalk-behind power mower 500 using a gear drive system, an exemplaryembodiment of which is partially illustrated in FIG. 14, may alsoutilize a control system 400 in accordance with the present invention(for clarity, only the right side of the mower 500 is illustrated inthis view).

[0069] The control system 400 may be similar in many respects to thecontrol system 200 described and illustrated herein. For example, it mayinclude hand grips 402, drive control levers 420, and OPC levers 440having generally the same configuration and functionality as that of therespective corresponding hand grips 202, drive control levers 220, andOPC levers 240 of the control system 200.

[0070] The exemplary gear drive system illustrated in FIG. 14 uses adriving pulley 504 powered by a prime mover (not shown) which issupported by a frame 502 of the mower 500. An endless belt 506 maytransmit power from the driving pulley 504 to a driven pulley 508, thelatter being attached to the respective drive wheel 509 (right drivewheel removed for clarity in FIG. 14). A gear selector (not shown) maybe provided to permit selection of driving speed and direction (forward,reverse) of the driving pulley 504.

[0071] An idler pulley 510 selectively tensions the belt 506 in responseto operator manipulation of the drive control lever 420. For example,when the drive control lever 420 is manipulated to a forward position F(see FIG. 18), e.g., a position generally similar to the forwardposition F of lever 220 shown in FIG. 5, a tie rod 422 causes a bellcrank 512 (see FIG. 14) to pivot about a pivot 514 in a first direction516. Movement of the bell crank 512 in the first direction 516 causesthe idler pulley 510 to tension the belt 506, providing driving power tothe drive wheel. Thus, the forward position F of the drive control lever420 corresponds to the respective drive wheel of the mower beingconfigured for driving operation (either forward or rearward movement,depending on the position of the transmission gear selector).

[0072] The bell crank 512 is preferably biased in the first direction516 by a spring (not shown) or other similar device such that the drivecontrol lever 420 is biased toward the forward position F (see FIG. 18).

[0073] When the drive control lever 420 is moved from the forwardposition F to a first or neutral position N (shown in FIGS. 15 and 16),e.g., to a position generally similar to the neutral position N of lever220 shown in FIG. 5, the tie rod 422 causes the bell crank 512 to pivotabout the pivot 514 in a second direction 518. Motion of the bell crank512 in the second direction 518 causes the idler pulley 510 to move awayfrom the belt 506. With belt tension relaxed, power to the drive wheel509 is reduced or terminated. Thus, the neutral position N of the drivecontrol lever 420 corresponds to the respective drive wheel 509 of themower 100 being in a neutral configuration, i.e., providingsubstantially no power or braking.

[0074] Preferably, further movement of the bell crank 512 in thedirection 518, e.g., movement of the drive control lever 420 to a secondor “park” position “P” (shown in FIGS. 17 and 19), may engage a wheelbrake 520. While not limited to any particular configuration, the wheelbrake 520 may be a friction band brake or other brake mechanism known inthe art, e.g., a disk brake. To engage the wheel brake 520, the bellcrank 512 may be coupled thereto, e.g., via a linkage 522, such thatmovement of the drive control lever 420 to the park position P resultsin braking of the respective drive wheel 509. Thus, the park position Pof the drive control lever 420 corresponds to the respective drive wheel509 of the mower 100 being in a park (e.g., braked) configuration.

[0075] The control system 400 may also include a latching device 470(shown in FIGS. 14-19) similar in most respects to the latching device270 described herein and illustrated in FIGS. 5-10. In the illustratedembodiments, the latching device 470 includes a pivoting, generallyhook-shaped latch member 473. However, other shapes are certainlypossible. In fact, the term “latching device” may include most anydevice operable to substantially retain the drive control lever 420 in apredetermined position until intentionally released (or otherwisemanipulated) by the operator.

[0076] FIGS. 15-19 illustrate end views of one hand grip 402 showing thelatching device 470 and drive control lever 420 in variousconfigurations. While only the latching device 470 associated with onehand grip (the right-hand grip) of the control system 400 is illustratedin FIGS. 15-19, the latching device 470 for the opposite hand grip (theleft-hand grip) is substantially the same, e.g., a mirror image, unlessotherwise described herein.

[0077] The latching device 470 is pivotable about a latch pivot axis 472that is preferably parallel and coincident (coaxial) to a grip axis ofthe hand grip 402 (much like the latch pivot axis 272 of the neutrallock 270 and the grip axis 201 as shown in FIGS. 5-6). The latchingdevice 470 may include a first lever seating surface 474 to assist insecurely latching the drive control lever 420 when the latter is in theneutral position N as generally shown in FIG. 15. That is, when thelatching device is engaged as shown in FIG. 15, the drive control lever420 is latched in the neutral position N.

[0078] To disengage the drive control lever 420 from the neutralposition N, the latching device 470 may be pivoted about the pivot axis472 in a direction 475 to a disengaged (unlatched) position illustratedin FIG. 16. To assist the operator with pivoting the latching device470, tabs, e.g., thumb tabs 476 and 478, which may be manipulated withthe operator's thumb or other finger, may be included. An optional,friction-reducing member/device, e.g., a roller 280 (see FIG. 15), maybe provided to assist with moving the latching device 470 relative tothe drive control lever 420. Similarly, as with the neutral lock 270, adevice (not shown) may be included to provide rotational resistance ofthe latching device 470 about the axis 472.

[0079] Once again, while illustrated in FIGS. 14 and 15-19 with anoutwardly opening mouth 471 (i.e., the opening formed by the latchingdevice 470 opens toward the outside of the mower 500), other embodimentsmay utilize a latching device 470 having an inwardly opening mouth 471similar to the embodiment of the neutral lock 270 illustrated in FIGS. 1and 2.

[0080] Once the latching device 470 is moved to the disengaged positionillustrated in FIG. 16, the drive control lever 420 is free to move fromthe neutral position N toward either the park position P of FIG. 17 ortoward the forward position F of FIG. 18 (the drive control lever 420may also be moved between the neutral position N of FIG. 15 and the parkposition P of FIG. 17 while the latching device 470 remains in theengaged position shown in FIG. 15).

[0081] To improve latching of the drive control lever 420 when thelatter is in the park position P, the latching device 470 may include asecond lever seating surface 481 as identified in FIGS. 15 and 17. Adiscontinuity, e.g., raised portion 483, preferably exists between thefirst seating surface 474 and the second seating surface 481. Thediscontinuity adequately isolates the two seating surfaces 474, 481 andprovides more positive latching of the drive control lever 420 in eitherof the selected positions.

[0082] When the drive control lever 420 is moved to the forward positionF as shown in FIG. 18, an optional pivot limiting device, e.g., ear 482,may prevent engagement of the latching device 470, e.g., limit rotationof the latching device 470 in the direction 484. FIG. 19 illustrates therelative locations of the drive control lever 420 and the latchingdevice 470 when the drive control lever 420 is in the park position Pand the latching device 470 is disengaged.

[0083] Thus, the latching device 470 permits latching of each drivecontrol lever 420 in two or more positions, e.g., in a neutral positionN (see FIG. 15) and in a park position P (see FIG. 17). Identifyingindicia 486 a and 486 b (see FIG. 19) may be included on each latchingdevice 470 to assist the operator in quickly identifying latching devicepositions. For example, indicia 486 a may include the letter “N” or theword “NEUTRAL” (or some equivalent) while indicia 486 b may include theletter “P” or the word “PARK” (or some equivalent).

[0084] Different indicia may be used to indicate other positions. Forexample, some embodiments may utilize latching devices having additional(e.g., three) or different latching positions. In this case, specificidentifying indicia corresponding to these additional/different latchingpositions may be provided without departing from the scope of theinvention.

[0085] The invention is not limited to the embodiments described aboveas other configurations are certainly also possible within the scope ofthe invention. For example, other embodiments may have hand gripsconfigured to extend downwardly and outwardly rather than upwardly andinwardly. That is, the hand grips may couple to the mower at or neartheir uppermost end and extend downwardly and outwardly therefrom.However, such embodiments may still result in grip axes, e.g., axes 201a and 201 b (see FIG. 2), that approach and/or intersect one anotherabove the grip assembly 203.

[0086] Exemplary embodiments of the present invention are describedabove. Other variations, modifications, and combinations of the variousparts and assemblies can certainly be made and still fall within thescope of the invention. Thus, the invention is limited only by thefollowing claims, and equivalents thereto.

What is claimed is:
 1. An operator control system for a self-propelledvehicle, the control system comprising: a handle assembly comprising afirst hand grip having a first grip axis and a second hand grip having asecond grip axis, wherein the first grip axis and the second grip axisextend upwardly and toward one another when the vehicle is in anoperating configuration; a first control lever associated with the firsthand grip, the first control lever pivotable about a first pivot axis,wherein the first pivot axis is substantially parallel to the first gripaxis of the first hand grip; and a latching device associated with thefirst control lever, the latching device adapted to latch the firstcontrol lever in two or more positions.
 2. The control system of claim1, wherein the two or more positions comprise a first position of thefirst control lever corresponding to a neutral configuration of a drivewheel of the self-propelled vehicle, and a second position of the firstcontrol lever corresponding to a park configuration of the drive wheel.3. The control system of claim 1, wherein the latching device comprisesa pivoting latch member coupled to an end of the first hand grip.
 4. Thecontrol system of claim 3, wherein the pivoting latch member ispivotable about a latch pivot axis that is substantially parallel to thefirst grip axis.
 5. The control system of claim 4, wherein the latchpivot axis is substantially coaxial with the first grip axis.
 6. Thecontrol system of claim 3, wherein the pivoting latch member comprisesone or more tabs to assist in the manipulation of the pivoting latchmember.
 7. The control system of claim 1, wherein the latching devicefurther comprises identifying indicia corresponding to at least one ofthe two or more positions.
 8. An operator control system for aself-propelled vehicle, the control system comprising: a handle assemblycomprising a first hand grip having a first grip axis and a second handgrip having a second grip axis, wherein the first grip axis and thesecond grip axis extend upwardly, forwardly, and toward one another whenthe vehicle is in an operating configuration; a first control leverassociated with the first hand grip, the first control lever pivotableabout a first pivot axis, wherein the first pivot axis is substantiallyparallel to the first grip axis of the first hand grip; and a latchingdevice associated with the first control lever, the latching deviceoperable to latch the first control lever in two or more positions. 9.The control system of claim 8, wherein the first grip axis and thesecond grip axis lie substantially in the same plane.
 10. The controlsystem of claim 8, wherein the first hand grip and the second hand gripform ends of the handle assembly.
 11. The control system of claim 8,wherein the latching device comprises a generally hook-shaped member,the hook-shaped member comprising lever seating surfaces to assist inlatching the first control lever in the two or more positions.
 12. Thecontrol system of claim 11, wherein the hook-shaped member comprises afriction-reducing member operable to facilitate engagement with thefirst control lever.
 13. The control system of claim 12, wherein thefriction-reducing member is a roller.
 14. The control system of claim 8,wherein the latching device is operable to permit latching of the firstcontrol lever in a first position corresponding to a neutralconfiguration of a first drive wheel of the self-propelled vehicle, anda second position corresponding to a park configuration of the firstdrive wheel.
 15. A method for controlling a self-propelled vehicle, themethod comprising: providing an operator control system comprising: ahandle assembly comprising a first hand grip having a first grip axisand a second hand grip having a second grip axis, wherein the first gripaxis and the second grip axis extend upwardly and toward one anotherwhen the vehicle is in an operating configuration; a first control leverassociated with the first hand grip, the first control lever pivotableabout a first pivot axis, wherein the first pivot axis is substantiallyparallel to the first grip axis of the first hand grip; and a firstlatching device associated with the first control lever, the firstlatching device operable to latch the first control lever in at least afirst position and a second position; grasping the first control leverwith an operator's first hand; manipulating the first control lever tothe first position with the operator's first hand; and manipulating thefirst latching device to latch the first control lever in the firstposition.
 16. The method of claim 15, further comprising: manipulatingthe first control lever to the second position with the operator's firsthand; and manipulating the first latching device to latch the firstcontrol lever in the second position.
 17. The method of claim 15,wherein the first position of the first control lever corresponds to aneutral configuration of a first drive wheel of the self-propelledvehicle, and the second position of the first control lever correspondsto a park configuration of the first drive wheel.
 18. The method ofclaim 15, further comprising manipulating the first latching device to adisengaged position to allow substantially unimpeded movement of thefirst control lever.
 19. The method of claim 15, wherein manipulatingthe first latching device comprises manipulating the first latchingdevice with a finger of the operator's first hand.
 20. The method ofclaim 15, further comprising: providing a second control leverassociated with the second hand grip, the second control lever pivotableabout a second pivot axis, wherein the second pivot axis issubstantially parallel to the second grip axis of the second hand grip;providing a second latching device associated with the second controllever; and selectively manipulating the second latching device betweenat least a first position and a second position.
 21. An operator controlsystem for a self-propelled power mower, the control system comprising:a handle assembly comprising a first hand grip having a first grip axisand a second hand grip having a second grip axis, wherein the first gripaxis and the second grip axis are substantially coplanar and extendupwardly, forwardly, and toward one another when the mower is in anoperating configuration; a first control lever associated with the firsthand grip, the first control lever pivotable about a first pivot axis,wherein the first pivot axis is substantially parallel to the first gripaxis of the first hand grip; and a first latching device comprising agenerally hook-shaped member pivotally coupled to the first hand gripand operable to pivot about an axis generally coaxial with the firstgrip axis, the first latching device adapted to latch the first controllever in at least a first position and a second position.
 22. Thecontrol system of claim 21, wherein the hook-shaped member comprises afirst lever seating surface to assist in latching the first controllever in the first position and a second lever seating surface to assistin latching the first control lever in the second position.
 23. Thecontrol system of claim 22, further comprising first indicia associatedwith the first lever seating surface and second indicia associated withthe second lever seating surface.
 24. The control system of claim 21,wherein the first position of the first control lever corresponds to aneutral configuration of a first drive wheel of the mower, and thesecond position of the first control lever corresponds to a parkconfiguration of the first drive wheel.
 25. The control system of claim21, further comprising: a second control lever associated with thesecond hand grip, the second control lever pivotable about a secondpivot axis, wherein the second pivot axis is substantially parallel tothe second grip axis of the second hand grip; and a second latchingdevice comprising a generally hook-shaped member pivotally coupled tothe second hand grip and operable to pivot about an axis generallycoaxial with the second grip axis, the second latching device adapted tolatch the second control lever in at least a first position and a secondposition.
 26. The control system of claim 25, wherein the first positionof the second control lever corresponds to a neutral configuration of asecond drive wheel of the mower, and the second position of the secondcontrol lever corresponds to a park configuration of the second drivewheel.
 27. A self-propelled, walk-behind or ride-behind lawn mower,comprising: a frame; a cutting deck attached to the frame; one or moredrive wheels operable to support the frame in rolling engagement with aground surface; a prime mover adapted to provide power to the one ormore drive wheels and the cutting deck; and an operator control systemoperatively coupled to the frame, the control system comprising: ahandle assembly comprising a first hand grip and a second hand grip,wherein the first hand grip and the second hand grip extend generallyupwardly and inwardly towards one another, and further wherein the firsthand grip and the second hand grip are forwardly inclined relative to avertical plane passing through a lowermost portion of one or both of thefirst hand grip and the second hand grip; a first control leverassociated with the first hand grip, the first control lever pivotableabout a first pivot axis; a second control lever associated with thesecond hand grip, the second control lever pivotable about a secondpivot axis, wherein the first pivot axis and the second pivot axisextend generally upwardly and inwardly towards one another, and furtherwherein the first pivot axis and the second pivot axis are forwardlyinclined relative to the vertical plane passing through the lowermostportion of one or both of the first hand grip and the second hand grip;and a latching device associated with at least the first control lever,the latching device adapted to latch the at least first control lever intwo or more positions.